Try to install Really simple SSL plugin to fix the SSL issue.
Reply back if it doesn’t help, and provide FTP access. Let us know if you have CDN, black and white lists.
About Elementor, do you mean this
[18-Jul-2022 06:38:04 UTC] PHP Deprecated: _register_skins is deprecated since version 3.1.0! Use Elementor\Widget_Base::register_skins() instead. in /var/www/vhosts/****e.de/httpdocs/wp-includes/functions.php on line 5379 – check this topic https://wordpress.org/support/topic/deprecated-_register_controls-is-deprecated-since-version-3-1-0-2/ and contact support of Elementor plugin.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.